1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.pool2;
18
19 import java.util.Objects;
20
21 /**
22 * A base implementation of {@code PoolableObjectFactory}.
23 * <p>
24 * All operations defined here are essentially no-op's.
25 * <p>
26 * This class is immutable, and therefore thread-safe
27 *
28 * @param <T> Type of element managed in this factory.
29 *
30 * @see PooledObjectFactory
31 * @see BaseKeyedPooledObjectFactory
32 *
33 * @since 2.0
34 */
35 public abstract class BasePooledObjectFactory<T> extends BaseObject implements PooledObjectFactory<T> {
36
37 /**
38 * No-op.
39 *
40 * @param p ignored
41 */
42 @Override
43 public void activateObject(final PooledObject<T> p) throws Exception {
44 // The default implementation is a no-op.
45 }
46
47 /**
48 * Creates an object instance, to be wrapped in a {@link PooledObject}.
49 * <p>This method <strong>must</strong> support concurrent, multi-threaded
50 * invocation.</p>
51 *
52 * @return an instance to be served by the pool, not null.
53 *
54 * @throws Exception if there is a problem creating a new instance,
55 * this will be propagated to the code requesting an object.
56 */
57 public abstract T create() throws Exception;
58
59 /**
60 * No-op.
61 *
62 * @param p ignored
63 */
64 @Override
65 public void destroyObject(final PooledObject<T> p) throws Exception {
66 // The default implementation is a no-op.
67 }
68
69 @Override
70 public PooledObject<T> makeObject() throws Exception {
71 return wrap(Objects.requireNonNull(create(), () -> String.format("BasePooledObjectFactory(%s).create() = null", getClass().getName())));
72 }
73
74 /**
75 * No-op.
76 *
77 * @param p ignored
78 */
79 @Override
80 public void passivateObject(final PooledObject<T> p) throws Exception {
81 // The default implementation is a no-op.
82 }
83
84 /**
85 * Always returns {@code true}.
86 *
87 * @param p ignored
88 *
89 * @return {@code true}
90 */
91 @Override
92 public boolean validateObject(final PooledObject<T> p) {
93 return true;
94 }
95
96 /**
97 * Wraps the provided instance with an implementation of
98 * {@link PooledObject}.
99 *
100 * @param obj the instance to wrap, should not be null.
101 *
102 * @return The provided instance, wrapped by a {@link PooledObject}
103 */
104 public abstract PooledObject<T> wrap(T obj);
105 }